Crassula coccinea holds a unique double distinction in the genus Crassula (family Crassulaceae): it is one of the oldest succulent species in European cultivation, having been grown in Britain since 1714 — over three centuries ago — and it produces some of the most vivid, truly tubular, scarlet-red flowers of any Crassula species, pollinated in the wild by a single remarkable butterfly. Known as the red crassula, and long traded under the synonym Rochea coccinea, this compact, fynbos-dwelling species from the Western Cape mountains deserves far more attention from growers than it currently receives. Its historical importance, its striking summer blooms, and its fascinating pollination ecology make it one of the most botanically interesting species in the entire genus.
Taxonomy and Naming History
Crassula coccinea was described by Carl Linnaeus in Species Plantarum in 1753. The accepted name is Crassula coccinea L. — one of the original ten Crassula species described by Linnaeus, alongside Crassula muscosa and others.
The species has a long synonymy reflecting its historical popularity and the many genera into which it was placed over the centuries:
- Rochea coccinea (L.) DC. — the most widely used synonym, still common in the trade
- Larochea coccinea (L.) Pers.
- Kalosanthes coccinea (L.) Haw.
- Danielia coccinea (L.) Lem.
- Dietrichia coccinea (L.) Tratt.
- Sedum rochea (L.) Kuntze
- Crassula versicolor Burch.
A nomenclatural note. POWO also accepts Crassula perfoliata var. coccinea (Sweet) G.D.Rowley as a separate, valid infraspecific taxon within Crassula perfoliata. The relationship between Crassula coccinea L. and Crassula perfoliata var. coccinea has been debated — some authors treat them as conspecific, others as distinct. POWO currently maintains both as accepted taxa. The plant treated here is Crassula coccinea L. sensu stricto: the compact, fynbos-dwelling species with tubular red flowers from the Western Cape mountains.
Etymology
The genus name Crassula derives from the Latin crassus (“thick, fat”). The specific epithet coccinea comes from the Greek kokkos, referring to the berry of the kermes oak (Quercus coccifera) from which a scarlet dye was historically produced — the word thus means “scarlet-coloured”, describing the vivid red flowers that make this species unmistakable.
Historical Significance — Three Centuries in European Gardens
Crassula coccinea was among the very first South African succulents to reach Europe. According to Kew’s records, it was introduced to Britain in 1714 by Professor Bradley of Oxford, who is known to have visited botanists and gardeners in Holland that year. The author of the text accompanying Sydenham Edwards’ plate of the species in Curtis’s Botanical Magazine wrote that when first introduced, the plant “was regarded as a kind of marvel of nature; even now that it is common, we scarcely know any succulent that is superior to it.”
For over a century, the species was cultivated as Rochea coccinea — the genus Rochea being subsequently absorbed into Crassula. It was one of the fashionable conservatory plants of the Georgian and Victorian eras in Britain and continental Europe, prized for its brilliant red flowers at a time when truly scarlet-flowered houseplants were rare. This historical context gives Crassula coccinea a cultural pedigree unmatched by any other species in the genus.
Natural Habitat and Distribution
Crassula coccinea is endemic to the Western Cape of South Africa, with a narrow coastal and montane distribution from the Cape Peninsula to Stilbaai (Still Bay). It grows in fynbos vegetation on quartzitic sandstone outcrops, in rock crevices, and on rocky mountain slopes, up to altitudes of approximately 800 m. This is strictly a fynbos species — it belongs to the Cape Floristic Region, the smallest and richest of the world’s six floral kingdoms.
Climate across the natural range
Rainfall. The Western Cape fynbos receives predominantly winter rainfall, with annual totals of 400–1,000 mm depending on altitude and proximity to the coast. Summers are warm and dry. The species grows in positions that are well-drained (rock crevices, sandstone ledges) and experience good air circulation — important for a plant susceptible to fungal infection.
Temperatures. The coastal mountains of the Western Cape experience mild, Mediterranean-type conditions: summer maxima of 25–32 °C, winter minima of 3–8 °C. Frost is occasional at altitude but generally brief. The species is rated for USDA zones 9a to 11b.
Botanical Description
Growth habit and stem
Crassula coccinea is a compact, sparingly branched, erect succulent shrublet, typically reaching 20–40 cm tall, occasionally up to 60 cm. Stems are erect to spreading, branching from the base, and slightly woody with age. The overall habit is neat and symmetrical.
Leaves
The leaves are arranged in four vertical rows (four-ranked), overlapping each other densely along the stems — a stacked arrangement that gives the plant a geometric, columnar appearance when not in flower. Leaves are flat, ovate to elliptic, up to 35 mm long and 15 mm wide, green to pale green, often with red-tinged edges, and with fine ciliate (hairy) margins. Older leaves turn brown but persist on the stems for a long time, creating a distinctive “bark” of dried foliage below the green growing tip.
Flowers — the scarlet spectacle
The flowers are the species’ crowning glory. They are produced in dense, flat-topped heads at the top of the stems in summer (December–March in the Southern Hemisphere; approximately June–August in the Northern Hemisphere). Individual flowers are tubular, about 10 mm across, and a brilliant, saturated scarlet red — not the pinkish-white or cream of most Crassula species, but a true, deep red. The flower heads are compact and showy, held above the foliage, and the display lasts for several weeks.
There is also a white-flowered form, as well as bicoloured variants, but the scarlet type is by far the most widely grown and sought-after.
Pollination — the Mountain Pride butterfly
The pollination ecology of Crassula coccinea is one of the most fascinating stories in the genus. In the wild, the species is pollinated by a single insect: the Mountain Pride butterfly, Aeropetes tulbaghia (also known as the Table Mountain Beauty). This large, chocolate-brown butterfly has an unusually long proboscis that reaches the nectar deep inside the narrow tubular flowers of Crassula coccinea.
What makes this relationship remarkable is that Aeropetes tulbaghia is one of very few butterflies in the world that is specifically attracted to red flowers — most butterflies prefer blue, purple, or yellow. The Mountain Pride pollinates a small guild of red-flowered fynbos species, including the iconic Red Disa (Disa uniflora), the Cluster Disa (Disa ferruginea), the Red Nerine (Nerine sarniensis), the April Fool (Haemanthus coccineus), and Crassula coccinea. These species share the same pollinator and, in some cases, overlap in flowering season, creating a red-flower pollination network unique to the fynbos mountains.
Cultivation Guide
Light requirements
Full sun to partial shade. In its fynbos habitat, the species grows in open, sunny, exposed positions. In cultivation, provide the brightest available position for the best flowering and most compact growth. Some afternoon shade in the hottest climates can prevent leaf scorching.
Temperature and hardiness
USDA zones 9a to 11b. Tolerates brief frost to approximately –4 °C to –6 °C depending on the source. Not suited to prolonged freezing or cold-wet conditions. In frost-prone climates, grow as a container plant that can be moved under cover in winter.
Substrate
Well-drained, sandy, acidic to neutral. The species is adapted to quartzitic sandstone-derived soils with excellent drainage and low fertility. A gritty, mineral-heavy mix (60% pumice/perlite/coarse sand, 40% organic) works well. Avoid alkaline or lime-rich substrates.
Watering
Water moderately during the growing season (autumn through spring in winter-rainfall areas; in cultivation, spring through summer for most growers). Reduce in the opposite season. The species is drought-tolerant but not as extreme in its aridity requirements as Karoo species — it comes from fynbos with 400–1,000 mm of winter rain.
Fungal susceptibility
This is an important cultural note: Crassula coccinea is susceptible to fungal infection, particularly rust. Good air circulation is essential — do not plant in a humid, stagnant, poorly drained position. The species is also reportedly sensitive to some fungal sprays, so chemical treatment should be used with caution. Prevention (good airflow, well-drained substrate, avoidance of overhead watering) is far more effective than cure.
Lifespan and replacement
The species grows fast and can flower in its first year from seed, but plants tend to become untidy after two to three years. SANBI recommends replacing plants regularly (every two to three years) rather than trying to maintain aging specimens. Take cuttings from vigorous young growth to maintain a succession of fresh plants.
Propagation
Seed — sow in autumn in shallow trays of sandy mix. Germination is usually very good, occurring within about three weeks. Seedlings can be potted individually as soon as they are large enough to handle.
Stem cuttings — root well in any sandy mixture at any time of year. Allow cuttings to callus for several days before inserting into the rooting medium.
Toxicity
As with other Crassula species, treat as potentially toxic to cats, dogs, and horses (ASPCA genus-level listing). No specific ethnobotanical or medicinal use is recorded for Crassula coccinea.
Frequently Asked Questions
Is Crassula coccinea the same as Rochea coccinea?
Yes — Rochea coccinea is a synonym of Crassula coccinea. The genus Rochea was absorbed into Crassula by modern taxonomic revisions, but the old name Rochea coccinea is still widely used in the horticultural trade and in older literature.
What pollinates Crassula coccinea in the wild?
The Mountain Pride butterfly (Aeropetes tulbaghia), one of very few butterflies worldwide that is specifically attracted to red flowers. This same butterfly pollinates several other iconic red-flowered fynbos species, including the Red Disa (Disa uniflora) and the Red Nerine (Nerine sarniensis). The tubular flower shape of Crassula coccinea matches the butterfly’s long proboscis.
How long has Crassula coccinea been cultivated in Europe?
Since 1714 — over 300 years. It was introduced to Britain by Professor Bradley of Oxford and was described as a “marvel of nature” in Curtis’s Botanical Magazine. It is one of the very first South African succulents to have been cultivated in Europe and was a fashionable conservatory plant throughout the Georgian and Victorian eras.
Why does my Crassula coccinea keep getting fungal problems?
Crassula coccinea is notably susceptible to fungal infection, particularly rust. It needs excellent air circulation and well-drained, sandy substrate. Avoid planting in humid, stagnant positions, and do not water from overhead. The species is also reported to be sensitive to some fungal sprays, so prevention through good cultural conditions is more effective than chemical treatment. Replace plants every two to three years to maintain vigour.
Sources and Further Reading
ASPCA Animal Poison Control — Jade Plant. aspca.org
Plants of the World Online (POWO), Royal Botanic Gardens, Kew — Crassula coccinea L. powo.science.kew.org
South African National Biodiversity Institute (SANBI), PlantZAfrica — Crassula coccinea. pza.sanbi.org
Royal Botanic Gardens, Kew — Crassula coccinea general information. powo.science.kew.org
Edwards, S. & Sims, J. Curtis’s Botanical Magazine. Plate of Rochea coccinea.
Tölken, H.R. (1985). Crassulaceae. In: Leistner, O.A. (ed.), Flora of Southern Africa, Vol. 14. Botanical Research Institute, Pretoria.
Eggli, U. (ed.) (2003). Illustrated Handbook of Succulent Plants: Crassulaceae. Springer, Berlin.
Rowley, G.D. (2003). Crassula: A Grower’s Guide. Cactus & Co. Libri, Venegono Superiore.
Goldblatt, P. & Manning, J. (2000). Cape Plants: A Conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.